1. Field of the Invention
The present invention relates to a lifting and lowering apparatus for a window, such as for use in opening and closing a window of an automobile. More particularly, the present invention relates to a window lifting and lowering apparatus capable of restricting lifting and lowering positions of the window.
2. Description of the Related Art
As a window lifting and lowering apparatus of an automobile, there has been proposed a single arm type window lifting and lowering apparatus for lifting and lowering window glass by pivoting an arm connected to window glass in an up and down direction. A conventional single arm type window lifting and lowering apparatus is constructed by using a sector gear in the shape of a circular arc pivoted by being brought into mesh with a pinion pivoted by a motor or the like. By pivoting an arm connected to the sector gear along with the sector gear, window glass connected to a front end of the arm can be moved in an up and down direction along an opening portion of a window or the like of an automobile. According to such a window lifting and lowering apparatus, since the apparatus typically requires a long movement range for lifting and lowering the window glass, there poses a problem that a diameter dimension and a length of the sector gear are prolonged in accordance therewith, and accordingly, the single arm type window lifting and lowering apparatus becomes large in size.
In order to resolve such a problem, the applicant has previously developed a single arm type window lifting and lowering apparatus utilizing a planetary gear mechanism to thereby realize small-sized formation of the window lifting and lowering apparatus. According to the window lifting and lowering apparatus developed by the applicant, a planetary gear mechanism is used along with a ring gear. By driving to rotate the planetary gear brought into mesh with the ring gear by a motor or the like, the planetary gear is pivoted at a reduced speed, and by engaging an arm connected to window glass to the planetary gear, the arm is pivoted at the reduced speed and the window glass is made movable.
However, according to this related art window lifting and lowering apparatus developed by the applicant, the planetary gear is pivoted without being restricted in a rotational amount thereof in the ring gear and therefore, when the window lifting and lowering apparatus is applied to a window of an automobile, a movable range of window glass cannot be restricted. Therefore, for example, in a sedan or the like, an upper movement position of the window is typically restricted by use of a window sash by causing the window glass to impinge to the window sash. On a lower side thereof, where a window sash is not present, however, a lower movement position of the window glass cannot be restricted and the window glass is operated to lower more than necessary. Further, in an automobile in which a window sash is not present even on an upper side of the window glass, such as a hard top type automobile, both the upper movement position and the lower movement position of the window glass cannot be restricted. Therefore, to ensure that the window does not lower or rise to far, the movement range of window glass is restricted by arranging a restricting member impinging to the window glass at the lower movement position or the upper and lower movement positions on the side of the body of an automobile. However, there remains a problem preferably to be improved further, in which the body structure of the automobile becomes complicated thereby and a degree of freedom of layout design of various parts in the body of the automobile is restricted.
It is an object of the invention to provide a window lifting and lowering apparatus for restricting the raising and lowering positions of a window without the need for a restricting member on the body side of an automobile and accordingly, realizing simplification of a structure thereof.
According to an aspect of the invention, there is provided a window lifting and lowing apparatus comprising an arm pivoted to lift and lower the window, a drive shaft operable to transmit a rotational force, and a speed reducing mechanism operable to reduce and transmit the rotational force produced by rotation of the drive shaft to the arm. In one embodiment, the speed reducing mechanism comprises a ring gear disposed in a fixed state, a planetary gear operable to pivotally move the arm by being rotated eccentrically in a state of being brought into mesh with the ring gear by the rotational force of the drive gear, and a restricting member integrated with the ring gear and operable to restrict a pivotal movement position of the planetary gear by impinging to a portion of the planetary gear.
Further, the portion of the planetary gear may include a stopper pin positioned in a circumferential direction of the planetary gear, and the restricting member may include a stopper gear in the shape of a circular ring integrated with the ring gear by being brought in mesh with the ring gear at an arbitrary pivotal movement position. Further, a portion of the stopper gear in a circumferential direction may include a stopper member which impinges with the stopper pin in the circumferential direction.
According to the window lifting and lowering apparatus of the invention, when the drive shaft is driven to rotate, the planetary gear is eccentrically pivoted inside of the ring gear in a state of being brought into mesh with teeth of the ring gear. As such, rotational force in a revolving direction in accordance with the pivotal movement of the planetary gear is transmitted to the arm, and the arm is pivotally moved at a reduced speed which then causes the window glass to be lifted and lowered. Further, in accordance with eccentric pivotal movement of the planetary gear, when a stopper pin provided at a portion of the planetary gear impinges to the stopper member provided at the stopper gear, pivotal movement of the planetary gear is restricted and pivotal movement of the arm is restricted to thereby restrict the movement position of the window glass. Therefore, small-sized formation of the window lifting and lowering apparatus can be realized without complicating the speed reducing mechanism. As such, the window lifting and lowering apparatus can be mounted to a small-sized vehicle. Further, it is not necessary to provide a structure for restricting movement of window glass on a body side of the automobile, and accordingly, simplification of an automobile structure can be realized.